There has been proposed a technique of performing three dimensional measurement of a desired object and creating a three dimensional model from measured data (e.g., disclosed in Document 1 [JP 2012-230594 A]). Document 1 discloses that, to create the three dimensional model of the desired object, surfaces constituting the desired object are obtained from positional data of a group of three dimensional points obtained by measurement with a laser scanner and intersections of the surfaces are calculated as outlines. In the process of obtaining the surfaces constituting the desired object, a non surface region which does not correspond to a flat or curved surface is excluded, and thereafter the surfaces are attached with labels and then continuous ones of the surfaces are unified based on the attached labels. Further, to create the three dimensional model, the technique disclosed in Document 1 obtains surfaces from the positional data of the group of three dimensional points which does not include points of the non surface regions, and further obtains boundaries of the surfaces obtained.
In some cases, for maintenance and repair of existing buildings and the like, estimation of requisite amounts of materials (e.g., interior cloth) would be required. In such estimation, it is necessary to determine whether materials are necessary for each part, and to determine amounts of the materials for each part. However, the technique disclosed in Document 1 only divides the surfaces based on the boundaries of the surfaces. Therefore, the three dimensional model created by this technique would not be useful for accurate estimation of requisite amounts of materials. To achieve such a purpose, it would be necessary to create an accurate dimensional drawing of the desired object.